Stringed musical instrument.



C. vB. RAUGH'.

STBINGED MUSICAL INSTRUMENT.

.APPLIUATIOI FILED 31126, 1911. 1

` Patented A110. 22, 1911.

UNITED STATES PATENT OFFICE..

CHARMESl B. RAUCH, F DAYTON, OHIO.

STBINGED MUSICAL INSTRUMENT.

Application filed January 25, 1911. Serial No. 604,537.

To all whom 'it mag/concern:

Be it known that I, CHARLES B. Ration, a citizen of the United States',- residing at Dayton, in the county of Montgomery and State of Ohio, have invented certain new and useful Improvements in' Stringed Musical Instruments; and I do declare the f ollowing to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, 'reference being had to the accompanying drawings, and to the letters' and figures of reference marked thereon, which form a part of this specification.

My invention relates to improvements in the construction lof. musical instruments such as mandolins and guitars. The improvements are applicable to the great range 'of stringed instruments, such as violins, mando-cellos, 'cellos, etc.

The main object of the invention 1s to increase the vibrating power of the instrument so Vthat-the musical sound waves shall lhave a greater volume and 4range of travel. In carrying out this object I s0 construct the front sounding board and the back board that.there is but asingle glued joint uniting them. This preserves to a greater extent the natural grain of the wood from which these parts are constructed. And further, I `interpose on the interior of the instrument a diaphragm which -is thinner at its circumference than elsewhere -and constitutes a delicate sounding board. The sound waves impinge against this sensitive member, and are thus prevented from contacting with the back of the instrument which is deadened by being held against the person of the performer.

In 'the accompanying drawings have illustrated a mandolin constructed in' accordance with the abovepbriefiy described features, and will now describe more in detail the essential features -both as to struc- :ture and functions.

In said drawings, Figure 1 is a plan viewof a mandolin with the-neck and a portion- 4of the front sounding board broken away.

Fig. 2 is a sectional view on the line aba of .F ig. 1, looking in either direction. Fig. 3

' is anedgeelevation of the instrument, showing the single joint between the meeting edges of the front sounding board and the .backp Fig. 4 is a transversesectional view on the line b b of Fig. .1.

lReferring to the specific parts as illustrated in the drawings and as indicated by` reference characters, 1 designates the front board, otherwise termed the front sounding board. This element is preferably constructed of a character of wood which is conspicuous on account of its freedom from an abundance of sap, such wood .for example as balsam, fir and the like. This front sounding board' is carved from a single piece of such material with the circumference terminated in a laterally turned rim 2. Inconstructing said board in such manner and iextending the rim 2 around theedge of the instrument, the natural grain of the wood is not intercepted at any point as would be the' case were the laterally extended rim 2 eliminated anda separate piece of material joined thereto to constitute such rim. The usual sound opening 3 and string supporting bridge' 4, are provided in and on said front sdunding board. The front portion 1v of said ,front sounding board is left with more body or material in order that a suitable reinforcement i'na'y be rovided to support the finger-board neckb '5 The back board 6 is Icarved .similarly to the' front sounding board, though the selection of wood is not so important in thev construction-of this member. Like the front sounding board 1, it is carved from a single piece of 'wood with the margin extended in a rim 6. The rim 6 and the -rim2 of the front sounding board, are united by means of glue, and thus it will be seen there is a sin le joint which unites the- `front and back 0I lthe in-l strument. The front portion 6 of the back is left with asuitable thickness, which coinbines with the similarly constructed portion .1 of the front sounding board-in providing a suitably reinforced portion for the support of the lin er-board neck 5. Like the front board 1, t e natural course of the rain of the wood from which the back boar is constructed, is not interfered with, but these two members are extended until their edges meet.

.The reinforcement for the Ytail piece consists of a block 7 in ter osed between the ends of the front and baci? boards 1 and 6, and there secured by means of glue. This reinforcing block 7 might extend in equal parts from the front and back boards and thus be integral parts of said boards. The ob- 4ect and pu Ilock is we understood and'requires no pose of the said reinforcing further reference than the statement that pin 82 entering said block2 holds one side of the tail piece while the strings of the instrument are connected with the other side. Such features beingno part of the present invention and being unnecessary fora proper elucidation of the invention, the strings and tail piece are omitted from the drawings.

Coming now to a very im ortant feature of my im rovement, it wil be seen from Figs. 1 an 2 that the inner side of the back board 6 is rovided with a ledge 8. This ledge exten s entirel around near the cin-` cumference of said oard, and provides a' support to which a diaphragm 9 is glued.

This diaphragm lies below the joint uniting the front and back boards, and it constitutes an inner sounding board. The circumference of this member is the only part which is in contact with any art of the structure, and owing to this and its construction, it has a most delicate vibratory quality. Thel peculiar construction of this member consists v1n forming the lower surface in convex,

while the upper side is substantially fiat or level. This produces a thin circumferential edgewhich alone engages the ledge 8. The

` location of this innerv sounding board and its effect is such as to prevent the sound waves from impin ing against the back of the instrument W ich has little or no vibratory quality. This must necessarily be the case when we consider that the backs of such in- 1, I soa.

struments are usually constructed with an first view to durability and not so much withA a view'to obtainin vibratory action and lastin resonance.` uitable o nin `10 are rovi ed -in the inner soun ing oard lor iaphragm to relieve the dead air chamber which would otherwise exist between said diaphragm and the back of the instrument.` The inner sounding board being thus of deli.- cate construction and free from anyresisting pressure below it, responds to the sound waves in a manner which 'ves great carry-- in effect to the tones pro uced.

aving described my invent-ion, I clailm: A stringed musical instrument havin its body formed of two equal parts united y a middle circumferential joint, the back portion of said body being provided with a marginal rabbet which extends continuously around the inner side of said back portion and forms thereon an integral oiset lying on one side "of said circumferential joint, and a plano-convex sounding board vhaving its relatively thin circumferential portion supported on said offset, substantially as specified.

In testimony whereof I atiix my signature, in presence of'two witnesses.

' ..z CHARLES B. RAUCH.

Witnesses LUolLn RAUGH, 'MATTHEW SEIBLER. 

